Lawn block system

ABSTRACT

A lawn defining system of co-acting slabs having upper surfaces specially angled to provide safe, efficient paths for rotary mowers, and having special stepped overlapping joints between slabs gapped beneath the overlap to allow relative motion and to prevent capillary action from drawing ground water into the joints; embodiments are provided for fence underlayment and for installation around building foundations.

United States Patent [19] Marvin 51 July 17,1973

[ LAWN BLOCK SYSTEM [76] Inventor: John R. Marvin, 7615 New Battle GroveRd., Baltimore, Md. 21222 [22] Filed: Dec. 1, 1971 [21] Appl. No.:203,596

[52] U.S. Cl 47/33, 94/31, 256/19, 52/ 102 [51] Int. Cl A01g 1/08 [58]Field of Search ..47/32-33; 94/31; 52/102; 256/19 [56] References CitedUNITED STATES PATENTS 2,235,356 3/1941 Byers 52/102 X 606,151 6/1898Johnson...

2,826,393 3/1958 Miller 256/19 1,916,494 7/1933 Schrickel 47/33 OTHERPUBLICATIONS Walks, Walls, Patio Floors, Sunset Book, Menlo Park,Calif., 1963, page 32 relied on.

Primary Examiner-Robert E. Bagwill Att0rneyJohn F. McClellan, Sr.

[57] ABSTRACT A lawn defining system of co-acting slabs having uppersurfaces specially angled to provide safe, efficient paths for rotarymowers, and having special stepped overlapping joints between slabsgapped beneath the overlap to allow relative motion and to preventcapillary action from drawing ground water into the joints; embodimentsare provided for fence underlayment and for installation around buildingfoundations.

I 6 Claims, 8 Drawing Figures Pmimwwm I 3745.701

JOHN 1Q MAEWN INVENTOR.

LAWN BLOCK SYSTEM This invention relates generally to edging andbordering systems and specifically to overlapping slab systems forground installation.

In the prior art various designs of overlapping slabs have beendisclosed for uses such as bordering cemetery lots, lawns, andstructures such as walls and buildmgs.

When properly made, installed, and maintained, such borders produce verybeautiful effects, enhancing property margins, fence lines, foundations,paths and the like. However, in spite of the desirability of such slabsystems, they are seldom seen anywhere except on institutional andgovernmental property. Costs of procurement and installation anddifiiculty of maintenance and lawn cutting have prevented widespread useof such systems around private dwellings and lawns.

Until the present time no system available for the purpose has foundwidespread acceptance and become the standard article of commerce forthe purpose.

One of the difficulties with prior-art systems is that water tends toaccumulate underneath the slabs and in the joints and on freezing, todislocate and even break the slabs.

Another difficulty of some prior art systems is that they fail toregulate the growth of grass and weeds so as to produce a sharp, cleanmargin on mowing. They cause this difficulty either by preventing mowingalongside or, in the case of flat portions of slabs, by allowinglow-lying grass to grow over the flat portions; such creeping growth isunsightly and difficult to remove except by hand.

A further problem has become very important with increasing use of thevertical spindle rotary mower. The numbers of injuries caused by theblades of such mowers when striking objects during mowing are makingpeople more careful about what they install in and around lawns. Theold-art devices which are low enough to permit mowing along the marginsdo not provide adequate warning means and means to prevent injury whenoverrun by rotary mowers. They can also damage reeltype mowers whenoverrun.

Objects of the present invention, therefore, are to provide a lawn blocksystem;

which is itself attractive in appearance and which allows close,regular, easy grass clipping to define lawns sharply and attractively;

which has safety features for preventing injury to people and equipmentwhen overrun during mowing, including a warning step, a safety marginbeyond the warning step, special non-siphoning joints, a non-rockingbase, and a non-trip, non-skid top surface; I

which is easy to install, requiring minimum preparation and effort;

which is adaptable for a wide varity of uses;

which requires little or no upkeep, and

which is economical, durable, and reliable.

The invention is characterized in general by overlapping slabs havingspecial cross-sectional shapes and accommodative, non-siphoning joints.

The above and other advantages and objects of the invention will becomemore readily apparent on examination of the following description,including the drawings, in which:

FIG. 1 is a plan view of a lawn block system along a fence line;

FIG. 2 is a side elevation taken at 22, FIG. 1;

FIG. 3 is a section taken at 3-3, FIG. 2, showing also a detail of alawnmower in use with the system;

FIG. 4 is a perspective view of a straight element of the system of FIG.1;

FIG. 5 is a joint detail in side elevation;

FIG. 6 is a plan view of corner elements of the system of FIG. 1;

FIG. 7 is an end section taken at 7-7, FIG. 8, of a second embodiment ofthe invention;

FIG. 8 is a perspective view of a system installed around a buildingfoundation.

In the Figures, which will now be taken up in detail, similar referencenumerals indicate similar parts.

FIG. 1 shows the Lawn Blocks System 10 of this invention in plan viewinstalled on a lawn L under a fence having posts P and rails R, portionsof which are shown. The blocks are preferably of concrete or similardurable material. The system includes straight blocks 12, which overlapin series to make a straight run, and corner blocks M, 116 which overlapeach other and the adjoining straight block to change direction of therun. For the use shown, the corner blocks are provided with structuredefining a hole 18 for the comerpost. A similar arrangengement definesholes in the straight blocks to accommodate line posts, at 18 betweenstraight blocks 12, 12".

FIG. 2 shows the elevation detail at 2-2, FIG. 1. Each block has anoverhang flange 20 at one end flush with the top and a lower flange 22at the other end flush with the bottom to form the overlap joints inseries assembly with other blocks.

FIG. 3 shows the cross-sectional view adjacent the post in FIG. 2. Eachof the blocks, including both straight and comer blocks, with andwithout holes, has the same shape in section. The blocks have a flat,horizontal surface 24 extending across the central portion of the top.The width of the horizontal portion of the top comprises a substantialfraction of the width of the block. The width of the block is made suchas to accommodate fence posts in the width of the horizontal surface,leaving the majority of the width of the block in sloping surfaces oneither side.

The horizontal surface breaks downward on either side into thesymmetrical flat surfaces 26, 28 which slope at a safety angle of a fewdegrees with respect to the top surface and which extends to the sidesof the block. The sides 30, 32 of the block are vertical and are lowrelative to the width of the block. The bottom of the block is plane andhorizontal with a central recess 34 leaving a footing 36, 38 at eitherside about half the width of the horizontal top surface.

These proportions provide several inventive advantages. The low profileof the block combined with the spaced footing feature permits the blockto be slipped into place beneath fence structure with little or nopreparation, and yet to be stable underfoot when pressed into theground. Fluctuations in ground temperature affect all blocks equally,freezing and thawing of ground has little or no effect under the center.The height of the block is such as to allow the wheel W of a mower M toroll freely onto the adjacent sloping surface 26 without fouling themower blade B, with the blade set to cut at the lowest positionordinarily provided for lawn mowing.

Grass growing at the side of the block is thus easily and quickly mowedby running the mower along the length of the block and other blocks inseries with it.

The relatively abrupt break in gradient at the junc tion between thesloping surface 26 and the top surface 24 gives the operator a warningwhen the wheel runs over the junction, so that the mower will not bepushed astraddle the block, possibly fouling the blade B. The horizontalsurface 24 at the top is just wide enough to provide a safety margin onwhich the wheel can travel before passing over into the straddlingposition, giving the operator time needed for correction, particularlywith a self-propelled mower. The horizontal top surface is preferablywide enough to contain the diameter of the posthole, but the greaterwidth is sloped to provide a width path for mower wheels.

FIG. 4 shows in perspective the proportions and the relations of the topand side surfaces, discussed in relation to FIG. 3, of a typical block12. The shape is strong, yet the block is relatively light for the size,so that it is easily handled in lengths which are several times thedimension of the width, which may be 8 inches in a preferred mode].

FIG. 5 illustrates the detail of the overlapping step joint which ischaracteristic of this invention. In the joints, the dimension of theoverhang flange measured in the direction of the length of the block isgreater than the corresponding dimension of the lower flange 22. The sumof the thicknesses of the overhang flange and the lower flange is lessthan the thickness of the block. These differences in dimension producethe not-quite-complementary structure of the joint overlap. In thevertical dimension this leaves a horizontal gap 42 between the bottom ofthe overhang 22 and the top of the lower flange. In the horizontaldimension this leaves a connecting vertical gap 44 between the end ofthe lower flange and the end 46 of the recess in the next block.

The upper portion of the two blocks butt together, forming flush,continuous top surfaces, aligned by the joint structure.

On installation only the lower gap 44 is below ground level. Grassconceals the upper gap 42. The upper gap provides room for a generousquantity of sealer to join the blocks and prevent vegetation frompenetrating up into the butt joint, where root and stem diameters wouldbe sufficient to wedge the joint apart, in contrast with the wide gaps42 and 44 which prevent such wedgmg.

The width of the lower gap also prevents capillary action from siphoningground water up between the walls of the joint where it could force theblocks apart or crack them on freezing. The footing structure 36, 38described in reference to FIG. 3 retards underflow of water from rainand melting snow, and tends to keep the bottom of the block assemblydry. Drainage from between the abutting ends of the top is shunted toeither side by the sealer 40.

FIG. 6 shows the overlap details of the corner blocks 14 and 16,including diagonal overlap structure 620, 622 and additionally shows therespective slots 48, 50 which comprise a circular post hole when thecorner bocks are assembled together.

FIG. 7 and FIG. 8 describe a second embodiment 80 of the invention. Inthis embodiment the blocks are largely similar in section and inproportion to the blocks of the first embodiment, except that the topsurfaces are different. The tops of the straight blocks 812 areassymetrical. Most of the top is taken up by sloping flat surfaces 826,leaving a horizontal flat surface 824 at one side 832, which is designedto fit against a structure, such as the dwwlling D shown. A similarcorner block 814 is provided. The joint structure throughout is the sameas that described in reference to FIG. 4, except that the overhangflanges of the adjacent blocks contact the side-sloping top faces 926,928 are somewhat wider and slope to thinner edges 930, 932 than theblocks; one end 954 is made vertical to abut the structure protected bythe splash block, and the opposite end 956 and top 924 slope away fromthe abutting end 954. The top is provided with an integral uprighttrough 958 for channeling flow toward the downslope end. Many of thesame advantages described in reference to the first embodiment will alsobe apparent in the provision for mowing to produce a clean marginwithout danger of fouling the blade.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed and desired to be secured by United States LettersPatent is:

l. A lawn block system comprising: plural overlapping means inhorizontal serial relation including first and second lawn blocks withstep overlaps, each of said lawn blocks having, as viewed in transversesection, a bottom with a central recess along the length thereof,leaving longitudinal footings along the bottom margins, a top with ahorizontal portion and a portion downwardly sloped from the horizontalportion; said horizontal portion extending a substantial fraction of thewidth of the lawn blocks and the downwardly sloped portion extending agreater fraction of said width than the horizontal portion; the firstlawn block step joint structure comprising a full width longitudinalflush extension of the top having a vertical surface on the end, thesecond lawn block step joint structure comprising a vertical surfacepositioned to form a butt joint with the end of the extension of thefirst lawn block and a full width longitudinal extension of the bottomprotrusive beyond said positioned vertical surface, the underneathsurface of the first lawn block extension and the upper surface of thesecond lawn block extension proportioned to space apart vertically onassembly of said system, thereby leaving drainage space including spacefor sealing-material at the bottom of said butt joint.

2. A lawn block system as recited in claim 1, wherein the extension ofthe first lawn block is longer than the extension of the second lawnblock, thereby on assembly leaving a horizontal spacing between the endof the second lawn block extension and the first lawn block, saidhorizontal spacing being connective with said vertical spacing, therebyleaving a second drainage space connective with the first said drainagespace.

3. A lawn block system as recited in claim 1, wherein all said lawnblocks are symmetrical in section about the centerline, said horizontaltop portion being paralllel longitudinally with the bottom and having asaid downsloping portion contiguous with both sides of the top.

4. A lawn block system as recited in claim 3, wherein the step jointoverlap structure between the first and second lawn blocks includesmatching vertical slots in the respective blocks, thereby forming a holefor a post.

5. A lawn block system as recited in claim 3, wherein at least a pair ofsaid blocks have matching said stepjoint overlap structures located at adiagonal angle to the longitudinal center lines thereof for therebyform- 5 ing a corner assembly, and have matching slots verti= callythrough the diagonally located step joint struczontal top portion islocated to one side of the block.

1. A lawn block system comprising: plural overlapping means inhorizontal serial relation including first and second lawn blocks withstep overlaps, each of said lawn blocks having, as viewed in transversesection, a bottom with a central recess along the length thereof,leaving longitudinal footings along the bottom margins, a top with ahorizontal portion and a portion downwardly sloped from the horizontalportion; said horizontal portion extending a substantial fraction of thewidth of the lawn blocks and the downwardly sloped portion extending agreater fraction of said width than the horizontal portion; the firstlawn block step joint structure comprising a full width longitudinalflush extension of the top having a vertical surface on the end, thesecond lawn block step joint structure comprising a vertical surfacepositioned to form a butt joint with the end of the extension of thefirst lawn block and a full width longitudinal extension of the bottomprotrusive beyond said positioned vertical surface, the underneathsurface of the first lawn block extension and the upper surface of thesecond lawn block extension proportioned to space apart vertically onassembly of said system, thereby leaving drainage space including spacefor sealing-material at the bottom of said butt joint.
 2. A lawn blocksystem as recited in claim 1, wherein the extension of the first lawnblock is longer than the extension of the second lawn block, thereby onassembly leaving a horizontal spacing between the end of the second lawnblock extension and the first lawn block, said horizontal spacing beingconnective with said vertical spacing, thereby leaving a second drainagespace connective with the first said drainage space.
 3. A lawn blocksystem as recited in claim 1, wherein all said lawn blocks aresymmetrical in section about the centerline, said horizontal top portionbeing paralllel longitudinally with the bottom and having a saiddownsloping portion contiguous with both sides of the top.
 4. A lawnblock system as recited in claim 3, wherein the step joint overlapstructure between the first and second lawn blocks includes matchingvertical slots in the respective blocks, thereby forming a hole for apost.
 5. A lawn block system as recited in claim 3, wherein at least apair of said blocks have matching said step-joint overlap structureslocated at a diagonal angle to the longitudinal center lines thereof forthereby forming a corner assembly, and have matching slots verticallythrough the diagonally located step joint structure, thereby forming aholde for a post.
 6. A lawn block system as recited in claim 2, whereinthe horizontal top portion of all said blocks is parallel longitudinallywith the bottom, and wherein the horizontal top portion is located toone side of the block.